Recently, the demand for data communication has been increasing in the field of mobile communication systems. As such, various techniques for higher utilization efficiency of frequency have been proposed for accommodating the increase in communication data caused by the data transmission demands. One of the techniques for improving the frequency utilization efficiency is the orthogonal frequency division multiple access (OFDMA). The OFDMA relates to a modulation method used for all cells within a communication area composed of cells to communicate with each other using the same frequency, and can realize faster data communication.
As for scheduling of transmission packets in an OFDMA system, a method is well-known in which mobile station apparatuses transmit, to a base station apparatus, channel quality indicator (CQI) which is information indicating reception quality of a downlink state for sub-carriers in wideband, while the base station apparatus performs packet scheduling based on the CQI of sub-carriers in wideband received from each mobile station apparatuses.
Additionally, a technique is also well-known in which for transmission packet scheduling in an orthogonal frequency division multiplexing (OFDM) system that utilizes a plurality of sub-carriers, mobile station apparatuses evaluate each channel states of a downlink (frequency characteristics, i.e., frequency-dependent characteristics of transmission losses) and transmit, to the base station apparatus, information obtained by quantizing each channel states, while the base station apparatus determines sub-carriers to be allocated for each mobile station apparatuses based on the transmitted information (Patent document 1).
FIG. 14 illustrates a communication method of the prior art between a base station apparatus and a mobile station apparatus. Having received downlink information of a downlink used for reception quality measurement from the base station apparatus, the mobile station apparatus measures reception quality of each channel based on the downlink information to create a channel profile of a propagation path.
The channel profile created by the mobile station apparatus is transmitted, from the mobile station apparatus to the base station apparatus, as reception quality information by using an uplink. Based on the reception quality information, the base station apparatus performs adaptive modulation and coding or frequency selective scheduling for signals to be transmitted from the base station apparatus to the mobile station apparatus.
As for transmission of the reception quality information to the base station apparatus by the mobile station apparatus, in Evolved Universal Terrestrial Radio Access studied under the third Generation Partnership Project (3GPP) which is international standardization project, it is studying that the reception quality information is transmitted by using a dedicated uplink control channel (Physical Uplink Control Channel, hereinafter referred to as “PUCCH”). And it is studying that an uplink data and the reception quality information are simultaneously transmitted by using an uplink data channel (Physical Uplink Shared Channel, hereinafter referred to as “PUSCH”).
For example, in the Non-Patent document 1, there is proposed a method to transmit, in transmitting the reception quality information from the mobile station apparatus to the base station apparatus, the reception quality information by using the PUCCH or the PUSCH depending on a kind of services different in required the reception quality information.
[Patent document 1] JP-A-2005-130491
[Non-Patent document 1] “CQI handling during DRX”, 3GPP, TSG RAN WG2 Meeting #58, R2-071901, May, 2007